The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Dec. 06, 1988
Filed:
May. 06, 1987
David N Kramer, Stevenson, MD (US);
Philip A Snow, Henderson, MD (US);
Other;
Abstract
Process and apparatus for the detection of hydrazine and hydrazine derivatives. For the detection of hydrazine and volatile hydrazine derivatives in air, preferred is a detector tube having iodate or periodate ion in a reactor zone and an iodine sensitive colorimetric indicator in a separate indicator zone. The colorimetric indicator may be an addition-complex type indicator, a redox sensitive dye precursor or an iodination type dye precursor. The hydrazine or hydrazine derivative contacts the iodate or periodate ion in the reactor zone to form iodine which diffuses or is drawn into the indicator zone where it contacts the indicator which then undergoes a color change. In a particularly preferred embodiment of the detector tube, an oxidizing metal ion is present in the reactor zone and, when a redox sensitive indicator is employed, in the indicator zone. The oxidizing metal ion in the reactor zone reacts with excess iodide ion to prevent its reaction with iodine to form the nonvolatile triiodide ion which, if formed, precludes diffusion of iodine into the indicator portion of the detector tube. The oxidizing metal ion in the indicator zone oxidizes iodide ion, formed as a result of the reaction of iodine with a redox sensitive indicator, back to iodine. The iodine thus formed is free to react with more of the indicator, thus enhancing sensitivity.